Hi Jack:

Am 24.02.17 02:17 schrieb(en) Jack:
SMTP over SSL: Connecting MTA frontier (smtp.frontier.com:smtp) failed: Error 
performing TLS handshake. An un expected TLS packet was received.

SMTP over SSL (aka SMTPS) uses service 'smtps' or 'ssmtp', which is bound to 
port 465, whereas smtp is port 25.  You can just omit the service part (i.e. 
just use 'smtp.frontier.com'), as port 465 is the default in this case.

With your setting (port 25), the remote MTA starts with sending the SMTP 
greeting instead of the TLS handshake, which triggers the error message above.

BTW, if you omit the service part for the other options (STARTTLS and unencrypted), the default 
port is 587 aka "submission", /not/ 25 aka "smtp", as this has been the setting 
in Balsa since ages.  The standard suggests using submission, but in practice almost all ISP's use 
smtp, though...

Require TLS: Connecting MTA frontier (smtp.frontier.com:smtp) failed: remote 
server does not support STARTTLS.

This may happen, although most ISP's offer STARTTLS these days, because the use of port 
465 for SMTPS has been officially withdrawn in 1998 (!!).  The TCP port 465 is now 
registered for "URL Rendesvous Directory for SSM", but in practice still being 
used for SMTPS...

Optional TLS: Connecting MTA frontier (smtp.frontier.com:smtp) failed: no 
suitable authentication mechanism.

As the remote server does not support STARTTLS, an unencrypted connection is 
established.  My new smtp implementation in this case limits the authentication 
mechanisms to those which do /not/ transmit your credentials in plain-text, 
i.e. with the current implementation to CRAM-MD5 or CRAM-SHA1 (given that MD5 
and SHA1 can be broken with some effort, this is not absolutely safe, but 
better than plain-text).  Either the remote server does not offer 
authentication for unencrypted connections at all (which would be a decent 
configuration), or only plain-text, which is a bad idea.

I then started googling, and found a message I sent to this list in 2011, suggesting 
using port 587 instead of 465.  At that point, I noticed the ":smtp" in the 
outgoing server (but not in the server for my other two mail hosts) and just removed it.  
Now it seems to work.

See above - for ssmtp, it now uses port 465...

BTW, I recently updated the README file with these explanations - maybe I 
should also adjust the help file...

Cheers,
Albrecht.

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